Does aortic crossclamping during the cooling phase affect the early clinical outcome of acute type A aortic dissection?

Can Open Distal Repair Be Safely Used in All Patients with Type A Acute Aortic Dissection?

PURPOSE

The distal suture line during aortic dissection repair can be performed by a closed technique or by an open technique. This study presents a retrospective comparison of both methods regarding their postoperative outcomes.

PATIENTS AND METHODS

120 patients who underwent surgery for acute aortic dissection type A were divided into two groups. In group A (n = 81), open distal anastomosis was performed under hypothermic circulatory arrest and selective cerebral perfusion. In group B (n = 39), distal anastomosis was performed with the aorta cross-clamped under mildly hypothermic cardiopulmonary bypass. Primary outcomes were operative mortality, neurologic morbidity, and long-term survival.

RESULTS

Hospital mortality (17.3% for the open group vs. 12.8% for the closed group, p = 0.53), permanent neurologic dysfunction (8.7% vs. 8.3%, p = 1.0), and temporary neurologic dysfunction (31.9% vs. 22.2%, p = 0.298) were not significantly different between groups. No significant difference in actuarial 5- and 10-year survival was observed (88% vs. 86% and 53 vs. 73%, respectively, p = 0.396). After propensity-score adjustment, the technique of distal aortic repair was not found to be a predictor of the primary outcomes.

CONCLUSION

We conclude that the open repair can be used in most if not all cases of surgical repair of type A acute aortic dissection.

sArterial cannulation to establish cardiopulmonary bypass during surgery for acute aortic dissection

A cannulation strategy in surgery for Stanford type A acute aortic dissection (AAAD) is integral for patient survival. Femoral cannulation has been the standard option for cannulation; however, there is increasing evidence that retrograde perfusion with femoral cannulation is associated with worse clinical outcomes, and new cannulation sites have been introduced in surgery for AAAD. Although axillary artery cannulation and central cannulation via the ascending aorta have become more popular than femoral access in recent years, adverse events have been reported and shifting cannulation sites during surgery are recommended by some surgeons. Therefore, it is beneficial for surgeons to broaden their knowledge about cannulation technology for AAAD. In this review, we discuss the various methods of cannulation for AAAD.

Evolution of surgical therapy for Stanford acute type A aortic dissection

Acute type A aortic dissection (AcA-AoD) is a surgical emergency associated with very high morbidity and mortality. Unfortunately, the early outcome of emergency surgical repair has not improved substantially over the last 20 years. Many of the same debates occur repeatedly regarding operative extent and optimal conduct of the operation. The question remains: are patients suffering from too large an operation or too small? The pendulum favoring routine aortic valve resuspension, when feasible, has swung towards frequent aortic root replacement. This already aggressive approach is now being challenged with the even more extensive valve-sparing aortic root replacement (V-SARR) in selected patients. Distally, open replacement of most of the transverse arch is best in most patients. The need for late aortic re-intervention has not been shown to be affected by more extensive distal operative procedures, but the contemporary enthusiasm for a distal frozen elephant trunk (FET) only seems to build. It must be remembered that the first and foremost goal of the operation is to have an operative survivor; additional measures to reduce late morbidity are secondary aspirations. With increasing experience, true contraindications to emergency surgical operation have dwindled, but patients with advanced age, multiple comorbidities, and major neurological deficits do not fare well. The endovascular revolution, moreover, has spawned innovative options for modern practice, including ascending stent graft and adaptations of the old flap fenestration technique. Despite the increasingly complex operations and ever expanding therapies, this life-threatening disease remains a stubborn challenge for all cardiovascular surgeons. Development of specialized thoracic aortic teams and regionalization of care for patients with AcA-AoD offers the most promise to improve overall results.

Open and closed distal anastomosis for acute type A aortic dissection repair

OBJECTIVES

The current consensus favours an open distal anastomosis for aortic dissection repair. A small number of experiences have compared early and long-term outcomes between closed and open distal anastomosis in the setting of acute aortic dissection.

METHODS

We reviewed our experience in 204 patients who underwent repair of spontaneous acute type A aortic dissection between January 2000 and December 2013. Open distal repair was performed in 109 patients, whereas 95 patients received a closed anastomosis. The clinical presentation, anatomical characteristics of aortic dissection, surgical techniques and the outcomes were analysed in the overall population and in the subgroup of patients (n = 100; open = 39, closed = 61) with Type 1 DeBakey dissection and a proximal intimal tear. Twenty-six preoperative and operative variables were studied to determine their impact on hospital mortality and postoperative neurological deficits. Imaging follow-up was available in 83 patients.

RESULTS

A more extensive involvement of the aortic arch characterized the open repair group. No differences in terms of mortality, morbidity and survival rates were observed between the two groups of patients. Open repair with cerebral perfusion was associated with a better neurological outcome. Patients who underwent an open distal anastomosis showed a significant higher rate of complete thrombosis of the false lumen.

CONCLUSIONS

An open repair does not increase the risk of early mortality and positively affect the evolution of the false lumen in distal unresected aortic segments. The use of cerebral perfusion reduces the risk of perioperative neurological injury.

Evidence, lack of evidence, controversy, and debate in the provision and performance of the surgery of acute type A aortic dissection

Acute type A aortic dissection is a lethal condition requiring emergency surgery. It has diverse presentations, and the diagnosis can be missed or delayed. Once diagnosed, decisions with regard to initial management, transfer, appropriateness of surgery, timing of operation, and intervention for malperfusion complications are necessary. The goals of surgery are to save life by prevention of pericardial tamponade or intra-pericardial aortic rupture, to resect the primary entry tear, to correct or prevent any malperfusion and aortic valve regurgitation, and if possible to prevent late dissection-related complications in the proximal and downstream aorta. No randomized trials of treatment or techniques have ever been performed, and novel therapies-particularly with regard to extent of surgery-are being devised and implemented, but their role needs to be defined. Overall, except in highly specialized centers, surgical outcomes might be static, and there is abundant room for improvement. By highlighting difficulties and controversies in diagnosis, patient selection, and surgical therapy, our over-arching goal should be to enfranchise more patients for treatment and improve surgical outcomes.

Recommendations for haemodynamic and neurological monitoring in repair of acute type a aortic dissection

During treatment of acute type A aortic dissection there is potential for both pre- and intra-operative malperfusion. There are a number of monitoring strategies that may allow for earlier detection of potentially catastrophic malperfusion (particularly cerebral malperfusion) phenomena available for the anaesthetist and surgeon. This review article sets out to discuss the benefits of the current standard monitoring techniques available as well as desirable/experimental techniques which may serve as adjuncts in the monitoring of these complex patients.